1. Field of the Invention
The present invention relates to devices, kits and methods for performing gene therapy, and more particularly to devices, kits and methods for performing gene therapy on an isolated region of a body lumen.
2. Description of Related Art
A living organism may suffer damage to its body lumens for a variety of reasons including normal deterioration, traumatic injury, and disease induced degradation. One particular area of concern is damage due to vascular disease, which affects a large segment of the human population where the leading cause of death is due to ischemic heart disease. Examples of current treatments for vascular disease include treating the vessels to remove damaged portions surgically, and treating damaged portions with balloon angioplasty to improve the performance of damaged tissues. During the course of balloon angioplasty, physical damage to body lumens is often a critical side effect of the treatment which results in restenosis. Other procedures lead to vessel trauma as well, for example vein bypass graft stenosis, prosthetic graft stenosis, and damage from other procedures. There are also several systemic-physiological problems that can lead to degradation of the body lumens including atherosclerosis, hypertension, angiogenesis, myocardial hypertrophy, and vascular smooth muscle cell (VSMC) hypertrophy. For example, in the case of chronic hypertension, it is thought that multiple factors play a role in determining susceptibility and degree of the problem.
Research on the vascular response to injury reveals that it involves alteration of several cellular processes: cell growth, cell migration and extracellular matrix production. This vascular response to injury is characteristic of the pathogenesis of various vascular diseases. For example, atherosclerotic lesions evolve as a result of vascular smooth muscle migration into the subintimal space, proliferation and the production of abundant extracellular matrix. In a similar fashion, restenosis after angioplasty, vein bypass graft stenosis, prosthetic graft stenosis, angiogenesis and hypertension all involve abnormalities in vascular cell growth, migration and matrix composition.
Several drugs are currently being used to treat vascular disease. However, one challenge to such drug treatments has been the development of a satisfactory method for delivering the drug to an effected segment of the body lumen. In the case of blood vessels, systemic delivery via the blood coursing through the vessel lumen is, of course, the most obvious route. However, many, if not most, of the proposed drugs have systemic side-effects which do not permit high dosages. Hence, the amount of drug available in the bloodstream will be small, resulting in a small concentration gradient in to the vessel wall.
One approach has been to insert a fluid delivery catheter into the lumen of a distal or proximal branch of the affected vessel and advance the drug delivery port to the vicinity of the lesion and then delivery a drug at high location concentration. One disadvantage of this technique is that the drug will only be at the lesion site for a short period of time since blood flow will rapidly sweep the drug downstream.
Catheters have also been used which include a balloon to occlude the lumen proximal and/or distal to the lesion to temporarily stop vessel flow during the treatment period. The disadvantage of this approach is that the patient may not be able to tolerate the stoppage of blood flow for more than a few minutes. It is thus important for the drug to be delivered and absorbed in as short a period as possible.
A need currently exists for improved devices, kits and methods for delivering drugs to vessel wall to treat vessel wall disease. Provided herein are embodiments of improved devices, kits and methods.